CASE-STUDY: Mercedes-Benz C-111 / III (Cd 0.178)

[aerohead]

I've wanted to post some case-studies of some "aero-modded" vehicles for the benefit of members and lurkers whom don't have access to some of the technical press.

The M-B 111/III knocked my socks off when I read about it, and I was still very impressed with the car when I got to see it first-hand at the Mercedes-Benz museum in 1997.



I can't format the material with tabs,'n such,so please forgive me for the "randomness" of the material.---------------------------------

The car	Mercedes-Benz 111/III
Height	1,029mm(41.16 inches)
Width	1,688mm(67.5 inches)
Length(competition)	4,784mm(191.36 inches)
Curb Weight	1,347 kg(2,965 pounds)
Power	171.58 kW(230-hp)
Final Drive	1.65:1
Engine	5-cyl TD with intercooler
Chassis	all-composite,fiberglass and carbon-fiber
Cd(competition)	0.195
Roof slope @ tail	11.5-degrees(my measurement)
Maximum cross-sectional area location	2,589mm(103.56 inches from nose)
Fineness-Ratio	4.64:1
Truncated Boat-Tail Length	700mm(28 inches)
.	.
PERFORMANCE	.
Top Speed @ Nardo Test-Track,Italy	315.157 km/h(195.398MPH)-continuous 24-hour driving.
Fuel Economy	6.26 km/l(14.7mpg) @ 195.398 mph

Development of the car included an investigation of a full boat-tail,which added 1500mm length to car and dropped drag to Cd0.178.

A compromise was set at 700mm,which reduced the cars "base-drag" of Cd0.2378 down to Cd0.195 (a 18% drag reduction)

The full boat-tail reduced drag of the base car by 25%.

In full-tail form,the C-111 has a fineness ratio of 6.106:1,which in free-stream,above ground-effect would equate to 3:1,near the ideal teardrop.

Reference: CAR and DRIVER,September,1978,also Dr.Hans Liebold,Research Engineer,M-B,Report,as cited in Hucho,page 142,2nd edition.

[aerohead]

Sorry,the Cd in the thread header should read Cd0.178,not 0.173(senior moments!)

[TestDrive]

Originally Posted by aerohead

I've wanted to post some case-studies of some "aero-modded" vehicles for the benefit of members and lurkers whom don't have access to some of the technical press.--------------------- The M-B 111/III knocked my socks off when I read about it, and I was still very impressed with the car when I got to see it first-hand at the Mercedes-Benz museum in 1997.---------------------------------- I can't format the material with tabs,'n such,so please forgive me for the "randomness" of the material.---------------------------------

Playing around with the newly introduced tables in the bb.

The car	Mercedes-Benz 111/III
Height	1,029mm(41.16 inches)
Width	1,688mm(67.5 inches)
Length(competition)	4,784mm(191.36 inches)
Curb Weight	1,347 kg(2,965 pounds)
Power	171.58 kW(230-hp)
Final Drive	1.65:1
Engine	5-cyl TD with intercooler
Chassis	all-composite,fiberglass and carbon-fiber
Cd(competition)	0.195
Roof slope @ tail	11.5-degrees(my measurement)
Maximum cross-sectional area location	2,589mm(103.56 inches from nose)
Fineness-Ratio	4.64:1
Truncated Boat-Tail Length	700mm(28 inches)
.	.
PERFORMANCE	.
Top Speed @ Nardo Test-Track,Italy	315.157 km/h(195.398MPH)-continuous 24-hour driving.
Fuel Economy	6.26 km/l(14.7mpg) @ 195.398 mph

(Reformated)
Development of the car included an investigation of a full boat-tail,which added 1500mm length to car and dropped drag to Cd0.178.

A compromise was set at 700mm,which reduced the cars "base-drag" of Cd0.2378 down to Cd0.195 (a 18% drag reduction)

The full boat-tail reduced drag of the base car by 25%.

In full-tail form,the C-111 has a fineness ratio of 6.106:1,which in free-stream,above ground-effect would equate to 3:1,near the ideal teardrop.

Reference: CAR and DRIVER,September,1978,also Dr.Hans Liebold,Research Engineer,M-B,Report,as cited in Hucho,page 142,2nd edition.

[tasdrouille]

I love that car

[red91sit]

The first "green" super car?!

[Christ]

Dorsal ridge - Stability at speed?

[red91sit]

or possibley veintilation - rear visibility?

[Christ]

Not louver... dorsal "fin".

It's not a fin, scientifically... fins are independently mobile. It's a dorsal "ridge". Unless it's mobile.

If it has any function at all, I'd assume stability, since that's what just about anything that still has a dorsal ridge uses it for.

Anyone else notice the close appearance likeness to most european exotics?

Put a boattail on a Lambo Diablo and you've got that car, basically. At least it seems that way to me. PhotoChop, anyone?

[TestDrive]

Originally Posted by tasdrouille

I love that car

Thanks for posting the picture.

[The Atomic Ass]

14.7mpg @ 195mph?!

DO WANT!

If it can do that at 195, I can only imagine what it gets at more sane speeds.